American Board of Ophthalmology (ABO) Practice Exam 2025 – The Complete All-in-One Guide to Exam Success

The ciliary body plays a crucial role in the production of aqueous humor, which is the clear fluid found in the anterior chamber of the eye. This fluid is essential for maintaining intraocular pressure, providing nutrients to the avascular structures of the eye, and facilitating the removal of metabolic wastes. The ciliary body contains the ciliary processes, which are finger-like projections that actively secrete aqueous humor into the posterior chamber, from where it flows into the anterior chamber.

The iris, which is the colored portion of the eye, is primarily responsible for controlling the size of the pupil and regulating the amount of light that enters the eye, but it does not produce aqueous humor. The cornea, while vital for focusing light, does not have a role in the production of this fluid; instead, it relies on the aqueous humor for nutrition and lubrication. The sclera, which forms the white outer layer of the eye, also does not participate in aqueous humor production and primarily provides structural support and protection for the eye.